JPWO2007069626A1 - Composite semipermeable membrane, production method thereof, and use thereof - Google Patents

Abstract

Provided is a composite semipermeable membrane having a high salt removal rate and high blocking performance against boron which is non-dissociated in a neutral region. When the polyamide separation functional layer is formed on the microporous support membrane, the polyamide molecule constituting the polyamide separation functional layer contains “two or more specific substituents, and at least one of them is β A specific cycloaliphatic compound or aromatic compound so as to include a partial structure represented by “a cycloaliphatic group or aromatic group containing a heteroatom bond having a carbonyl group at the position or γ-position” A composite semipermeable membrane is produced using an organic solvent solution.

Description

  The present invention relates to a composite semipermeable membrane useful for selective separation of a liquid mixture and a method for producing the same. For example, the present invention relates to a composite semipermeable membrane in which a polyamide separation functional layer is formed on a microporous support membrane, which can be suitably used for removing solute components such as boron from seawater or brine, and a method for producing the same.

  In recent years, seawater desalination using a composite semipermeable membrane has been attempted and has been put to practical use in water treatment plants around the world. The composite semipermeable membrane generally has a structure of a composite membrane in which a separation functional layer is coated on a microporous support membrane. When the separation functional layer is formed from a cross-linked aromatic polyamide, it can be easily obtained by the advantage of being rigid due to the inclusion of a benzene ring and the interfacial polycondensation of an aromatic polyfunctional amine and an aromatic polyfunctional acid halide. There is an advantage that a film can be formed, and further, there are advantages such as a high salt removal rate and a high permeation flux (see Patent Documents 1 and 2).

  Recently, advanced water quality standards are required for fresh water obtained by desalinating with a composite semipermeable membrane, and the requirements for the removal performance of the composite semipermeable membrane are becoming stricter. In particular, the required level for the removal performance of boron contained in trace amounts in seawater is becoming stricter.

  However, it is difficult to reduce the boron content to a concentration level that can be used for drinking water by a conventional desalination treatment using a normal composite semipermeable membrane.

Therefore, as means for improving the boron removal performance of the composite semipermeable membrane, for example, a method of hydrothermally treating the composite semipermeable membrane module (see Patent Document 3), the formed polyamide separation functional layer is converted into a bromine-containing free chlorine aqueous solution. A method of contacting (see Patent Document 4) has been proposed. However, in these composite semipermeable membranes, when the seawater with 25 ° C., pH 6.5, boron concentration of 5 ppm, TDS concentration of 3.5 wt% was permeated at an operating pressure of 5.5 MPa, the membrane permeated. Development of a composite semipermeable membrane having a flux of 0.5 m ³ / m ² / day or less and a boron removal rate of about 91 to 92% is still insufficient even at a high level and has a higher boron blocking performance. It was desired.

  In order to improve the solute blocking performance of the composite semipermeable membrane, the pore size in the separation functional layer of the composite semipermeable membrane may be reduced, but at the same time, the pore size should be set appropriately to obtain sufficient water permeability. It is also necessary to enlarge it. On the other hand, even if the pore size in the separation functional layer of the composite semipermeable membrane is small, if the number of pores is large and the amount of pores in the semipermeable membrane is large, the water permeability increases, but on the other hand, the solute blocking performance Tend to decline. Therefore, in order to improve the solute blocking performance and maintain the water permeability at an appropriate level, it is necessary to appropriately adjust both the pore diameter and the amount of pores in the separation functional layer of the composite semipermeable membrane.

Therefore, it is considered to improve the performance of the composite semipermeable membrane formed by forming the polyamide separation functional layer on the microporous support membrane by appropriately adjusting both the pore diameter and the amount of pores in the separation functional layer. Has been. As one of the means for solving the problem, there is a method of appropriately adjusting both the pore diameter and the amount of pores by adding a novel reactant to the reactant solution. For example, a composite semipermeable membrane contains a polyamine component having two or more amino groups in the molecule and a linear aliphatic polyacid halide having two or more halogenated acyl groups in the molecule as a novel reactant. A method of forming a crosslinked polyamide by reacting with an acid component has been proposed (see Patent Document 5). It is stated that this method can be carried out with a slight modification to the conventional production method, is useful as a simple improvement method, and can produce a composite semipermeable membrane having a high salt rejection and a high permeation flux. Yes. However, this method has not yet improved the boron rejection rate to a sufficient level.
JP-A-1-180208 Japanese Patent Laid-Open No. 2-115027 JP-A-11-19493 JP 2001-259388 A Japanese Patent No. 3031763

  The present invention provides a composite semipermeable membrane that exhibits a high salt removal rate and a high blocking performance against non-dissociated substances in a neutral region such as boric acid, and a method for producing the same. Objective.

  The present invention for achieving the above object is specified as follows.

  A composite semipermeable membrane in which a polyamide separation functional layer is formed on a microporous support membrane, and the polyamide constituting the polyamide separation functional layer includes a cyclic aliphatic group and / or an aromatic group in a molecular chain And the cycloaliphatic group and / or aromatic group has two or more groups represented by any of the following formulas (1) or (2) as substituents, and the substitution thereof A composite semipermeable membrane, wherein at least one of the groups is a group represented by the following formula (1).

(In the formula, n represents 0 or 1. X represents O, S, or NR ^5. R ¹ , R ² , and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ^At least ^one of R ¹ and R ² is a hydrogen atom, and R ³ and R ⁴ are a hydrogen atom or an alkyl or aromatic group having 1 to 12 carbon atoms that may have a substituent other than a carboxy group. R ¹ and R ³ may be covalently bonded to form a ring structure, and A represents a hydroxyl group or an amino group in a polyamide molecule, and represents at least one of two or more substituents. A is an amino group in the polyamide molecule.)
Here, the polyamide constituting the polyamide separation functional layer has a polyfunctional amine aqueous solution and two or more groups represented by any of the following formulas (3) or (4) as substituents. At least one of them is brought into contact with an organic solvent solution containing a cycloaliphatic compound and / or an aromatic compound, which is a group represented by the following formula (3), on a microporous support membrane and interfacial polycondensation It is a cross-linked polyamide obtained by making it.

(In the formula, n, X and R ^{1 to} R ⁵ are as defined above. Z represents a halogen atom.)
And the above-mentioned composite semipermeable membrane of the present invention can be manufactured by the following method.

  When the polyamide separation functional layer is formed on the microporous support membrane, the polyfunctional amine aqueous solution and the polyfunctional acid halide are contained, and the group represented by either the formula (3) or (4) is added. Two or more substituents, and at least one of the substituents is a cyclic aliphatic compound and / or an aromatic compound that is a group represented by the formula (3), the polyfunctional acid halide A polyamide separation functional layer is formed by bringing a 5 mol% or more organic solvent solution into contact with the microporous support membrane.

  ADVANTAGE OF THE INVENTION According to this invention, it can be set as the composite semipermeable membrane which has high desalination performance and can also block the non-dissociation substance in a neutral region with a high removal rate. That is, when the composite semipermeable membrane of the present invention is used as a separation membrane for water treatment, especially when seawater desalination treatment is performed, boron, which has been difficult to block with the prior art, is blocked with a sufficiently high removal rate. can do. As a result, it becomes possible to produce high-quality water that complies with advanced drinking water standards through desalination treatment by reverse osmosis treatment of seawater.

It is a graph which shows the relationship between a membrane permeation | transmission flux and a boron removal rate of the composite semipermeable membrane produced in Examples 1-15 and Comparative Examples 1-3.

  The composite semipermeable membrane of the present invention is a composite semipermeable membrane formed by forming a polyamide separation functional layer on a microporous support membrane, and the polyamide constituting the polyamide separation functional layer has a specific molecular chain. It contains a cyclic aliphatic group and / or an aromatic group.

  This specific cycloaliphatic group and / or aromatic group has two or more groups represented by any of the following formulas (1) or (2) as substituents, and At least one of the substituents is specified by being a group represented by the following formula (1). That is, it includes a heteroatom bond having a carbonyl group at the β-position or γ-position represented by the following formula (1). The cycloaliphatic group and / or aromatic group specified in this way is hereinafter referred to as “cycloaliphatic group and / or aromatic group having a specific substituent”. The cyclic aliphatic group and / or aromatic group having the specific substituent is a cyclic group having at least one group represented by the following formula (1) and one group represented by the following formula (2) as a substituent. It is roughly classified into an aliphatic group and / or an aromatic group, and a cyclic aliphatic group and / or an aromatic group having two or more groups represented by the following formula (1) as substituents. be able to.

(In the formula, n, X, R ^{1 to} R ⁵ , and A follow the definition described above.)
In order to introduce the cycloaliphatic group and / or aromatic group having the specific substituent into the molecular chain of the polyamide, when polyfunctional amine and polyfunctional acid halide are subjected to interfacial polycondensation, the following formula ( A specific cycloaliphatic compound and / or aromatic compound having the group represented by either 3) or (4) as a substituent may be present together.

  This specific cycloaliphatic compound and / or aromatic compound has two or more groups represented by any of the following formulas (3) or (4) as substituents, and At least one of them is specified by being a group represented by the following formula (3). The cycloaliphatic compound and / or aromatic compound thus specified is hereinafter referred to as “cycloaliphatic compound and / or aromatic compound having a specific substituent”. The cyclic aliphatic compound and / or aromatic compound having the specific substituent is a cyclic group having at least one group represented by the following formula (3) and one group represented by the following formula (4) as a substituent. When it is an aliphatic compound and / or an aromatic compound, and when it is a cyclic aliphatic compound and / or an aromatic compound having two or more groups represented by the following formula (3) as substituents be able to.

(In the formula, n, X, and R ^{1 to} R ⁵ are as defined above. Z represents a halogen atom.)
Specifically, the polyfunctional amine aqueous solution and the organic solvent solution containing the above-described cyclic aliphatic compound and / or aromatic compound having the specific substituent are brought into contact with each other on the microporous support membrane to cause interfacial polycondensation. Thus, it is produced by forming a polyamide separation functional layer on the microporous support membrane. Here, it is preferable that the organic solvent solution containing the cyclic aliphatic compound and / or the aromatic compound having the specific substituent described above further contains a polyfunctional acid halide. Moreover, it is preferable that at least one of the polyfunctional amine or the polyfunctional acid halide contains a trifunctional or higher functional compound.

  More specifically, as described later, the composite semipermeable membrane of the present invention is a polyfunctional amine aqueous solution in a method for producing a composite semipermeable membrane by forming a polyamide separation functional layer on a microporous support membrane. And an organic solvent solution containing a polyfunctional acid halide and containing 5 mol% or more of the above-described cyclic aliphatic compound and / or aromatic compound having the specific substituent with respect to the polyfunctional acid halide, It can be produced by forming a polyamide separation functional layer by contacting and interfacial polycondensation on a microporous support membrane.

  The thickness of the polyamide separation functional layer in the composite semipermeable membrane is usually within a range of 0.01 to 1 μm, preferably within a range of 0.1 to 0.5 μm, in order to obtain sufficient separation performance and a function of the amount of permeated water. And it is sufficient.

  Here, the polyfunctional amine refers to an amine having at least two primary and / or secondary amino groups in one molecule. For example, two amino groups are any of ortho, meta, and para positions. Aromatic polyfunctional amines such as phenylenediamine, xylylenediamine, 1,3,5-triaminobenzene, 1,2,4-triaminobenzene and 3,5-diaminobenzoic acid bonded to benzene in the positional relationship of Aliphatic amines such as ethylenediamine and propylenediamine, alicyclic polyfunctional amines such as 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, piperazine, 1,3-bispiperidylpropane and 4-aminomethylpiperazine be able to. Of these, aromatic polyfunctional amines having 2 to 4 primary and / or secondary amino groups in one molecule are preferred in consideration of selective separation, permeability, and heat resistance of the membrane. As the functional aromatic amine, m-phenylenediamine, p-phenylenediamine, and 1,3,5-triaminobenzene are preferably used. Among these, it is more preferable to use m-phenylenediamine from the standpoint of availability and ease of handling. These polyfunctional amines may be used alone or in combination of two or more.

  The polyfunctional acid halide refers to an acid halide having at least two carbonyl halide groups in one molecule. Examples of trifunctional acid halides include trimesic acid chloride, 1,3,5-cyclohexanetricarboxylic acid trichloride, 1,2,4-cyclobutanetricarboxylic acid trichloride, and bifunctional acid halides include biphenyl dicarboxylic acid. Aromatic difunctional acid halides such as acid dichloride, azobenzene dicarboxylic acid dichloride, terephthalic acid chloride, isophthalic acid chloride, naphthalene dicarboxylic acid chloride, aliphatic difunctional acid halides such as adipoyl chloride, sebacoyl chloride, cyclopentane Examples thereof include alicyclic difunctional acid halides such as dicarboxylic acid dichloride, cyclohexane dicarboxylic acid dichloride, and tetrahydrofuran dicarboxylic acid dichloride. Considering the reactivity with the polyfunctional amine, the polyfunctional acid halide is preferably a polyfunctional acid chloride, and considering the selective separation property and heat resistance of the membrane, 2 to 4 per molecule. The polyfunctional aromatic acid chloride having a carbonyl chloride group is preferred. Among them, it is more preferable to use trimesic acid chloride from the viewpoint of easy availability and easy handling. These polyfunctional acid halides may be used alone or in combination of two or more.

  The composite semipermeable membrane of the present invention has the above-mentioned “cyclic aliphatic group and / or aromatic group having a specific substituent” in the molecular chain of the polyamide constituting the separation functional layer formed on the microporous support membrane. Thus, boron removal performance higher than that of the prior art can be exhibited.

  Further, the method for causing the “cyclic aliphatic group and / or aromatic group having a specific substituent” to exist as a partial structure in the polyamide molecular chain constituting the separation functional layer is not particularly limited, For example, a solution containing the “cycloaliphatic compound and / or aromatic compound having the specific substituent” on the surface of the separation functional layer formed by interfacial polycondensation of a polyfunctional amine and a polyfunctional acid halide. "Cyclic aliphatic group and / or aromatic group having a specific substituent" may be introduced by the method of contacting with each other, or when polyfunctional amine and polyfunctional aromatic acid halide are subjected to interfacial polycondensation The “cyclic ring having a specific substituent” can be covalently bonded to the polyamide constituting the separation functional layer by allowing the “cycloaliphatic compound and / or aromatic compound having the specific substituent” to coexist in It may be introduced an aliphatic group and / or an aromatic group ".

  That is, in forming the polyamide separation functional layer on the microporous support membrane, a polyfunctional amine aqueous solution, an organic solvent solution containing a polyfunctional acid halide, the above-mentioned cyclic aliphatic compound having a specific substituent and / or A polyamide separation functional layer may be formed by contacting an organic solvent solution containing an "aromatic compound" on a microporous support membrane to cause interfacial polycondensation, or a polyfunctional amine aqueous solution and a polyfunctional acid. A polyamide separation functional layer is obtained by contacting a halide and an organic solvent solution containing the above-mentioned “cycloaliphatic compound and / or aromatic compound having a specific substituent” on a microporous support membrane to cause interfacial polycondensation. It may be formed.

In particular, a polyfunctional amine aqueous solution, a polyfunctional acid halide, and an organic solvent solution containing the above-mentioned “cyclic aliphatic compound and / or aromatic compound having the specific substituent” The ratio of “cycloaliphatic compound and / or aromatic compound” is preferably 5 mol% or more) and is produced by a method in which a polyamide separation functional layer is formed by contact and polycondensation on a microporous support membrane. The composite semipermeable membrane satisfies the following formula (5) when seawater having a pH of 6.5, a boron concentration of 5 ppm, and a TDS concentration of 3.5 wt% is permeated at an operating pressure of 5.5 MPa. Furthermore, since the membrane permeation flux is 0.5 m ³ / m ² / day or more and the boron removal rate can satisfy 94% or more, the boron removal performance is higher than that of the prior art. be able to.

  Among such “cycloaliphatic compounds and / or aromatic compounds having a specific substituent”, one group represented by the formula (3) and one group represented by the formula (4) are used as substituents. Those having the above include 2-chlorocarbonylmethoxybenzoyl chloride, 3-chlorocarbonylmethoxybenzoyl chloride, 4-chlorocarbonylmethoxybenzoyl chloride, 2,3-bischlorocarbonylmethoxybenzoyl chloride, 2,4-bischlorocarbonylmethoxybenzoyl Chloride, 2,5-bischlorocarbonylmethoxybenzoyl chloride, 2,6-bischlorocarbonylmethoxybenzoyl chloride, 3,4-bischlorocarbonylmethoxybenzoyl chloride, 3,5-bischlorocarbonylmethoxybenzoyl chloride, 2-chlorocarbon Bonylmethoxycyclohexanecarbonyl chloride, 3-chlorocarbonylmethoxycyclohexanecarbonyl chloride, 4-chlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,3-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,4-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 2, 5-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,6-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 3,4-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 3,5-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 3-chlorocarbonyl Methoxyphthaloyl chloride, 4-chlorocarbonylmeth Cyphthaloyl chloride, 2-chlorocarbonylmethoxyisophthaloyl chloride, 4-chlorocarbonylmethoxyisophthaloyl chloride, 5-chlorocarbonylmethoxyisophthaloyl chloride, 2-chlorocarbonylmethoxyterephthaloyl chloride, 1-chlorocarbonylmethoxycyclohexane -2,3-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-2,4-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-2,5-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-2,6- Dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-3,4-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-3,5-dica And lubonyl dichloride.

  In addition, among the “cycloaliphatic compound and / or aromatic compound having a specific substituent”, those having two or more groups represented by the formula (3) as substituents include (2-chlorocarbonylmethoxy Phenoxy) acetyl chloride, (3-chlorocarbonylmethoxyphenoxy) acetyl chloride, (4-chlorocarbonylmethoxyphenoxy) acetyl chloride, (2,3-bischlorocarbonylmethoxyphenoxy) acetyl chloride, (2,4-bischlorocarbonylmethoxy) (Phenoxy) acetyl chloride, (3,5-bischlorocarbonylmethoxyphenoxy) acetyl chloride, (2-chlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (3-chlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (4 Chlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (2,3-bischlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (2,4-bischlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (3,5-bischlorocarbonylmethoxycyclohexyloxy) ) Acetyl chloride, (2-chlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, (3-chlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, (2,3-bischlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, ( 2,4-bischlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, and the like.

  The above compounds may be used alone or in combination of two or more.

The composite semipermeable membrane obtained by such a production method has a TDS permeability coefficient when seawater having a temperature of 6.5 ° C., a pH of 6.5, a boron concentration of 5 ppm, and a TDS concentration of 3.5 wt% is permeated at an operating pressure of 5.5 MPa. When the film structure is such that is 0.1 × 10 ⁻⁸ m / s or more and 3 × 10 ⁻⁸ m / s or less, particularly excellent boron removal performance can be obtained. Here, TDS means Total Dissolved Solid, and the TDS concentration is an index representing the salt concentration of seawater.

  The TDS permeability coefficient can be obtained by the following method for obtaining the solute permeability coefficient. The following equation is known as a transport equation of the reverse osmosis method based on non-equilibrium thermodynamics.

Here, Jv is the membrane permeation volume flux (m ³ / m ² / s), Lp is the pure water permeability coefficient (m ³ / m ² / s / Pa), ΔP is the pressure difference (Pa) on both sides of the membrane, σ Is the solute reflection coefficient, Δπ is the osmotic pressure difference (Pa) on both sides of the membrane, Js is the solute permeation flux (mol / m ² / s), P is the solute permeability (m / s), and Cm is the solute membrane. The surface concentration (mol / m ³ ), Cp is the permeate concentration (mol / m ³ ), and C is the concentration on both sides of the membrane (mol / m ³ ). The average concentration C on both sides of the membrane has no substantial meaning when the concentration difference between the two sides is very large as in a reverse osmosis membrane. Therefore, the following formula (10) obtained by integrating the formula (9) with respect to the film thickness is frequently used as an approximate formula.

  However, F is following Formula (11) and R is a true rejection rate, Comprising: It defines by following Formula (12).

  Here, by changing ΔP variously, Lp can be calculated from the equation (7), R is measured by changing Jv variously, and R and 1 / Jv are plotted (9), (10 P (solute permeability coefficient) and σ (solute reflection coefficient) can be obtained simultaneously by curve fitting.

In the composite semipermeable membrane of the present invention, the microporous support membrane is a microporous membrane having substantially no separation performance of ions or the like, and can substantially give strength to the separation functional layer. Is. The size and distribution of the microporous holes are not particularly limited. For example, the microporous pores have gradually large pores from the surface on the side where the separation functional layer is formed to the other surface, and are separated. A support membrane in which the size of the micropores is 0.1 nm or more and 100 nm or less on the surface on the side where the functional layer is formed is not particularly limited, but the material used for the microporous support membrane and the shape thereof are not particularly limited. A microporous membrane made of polysulfone, cellulose acetate, polyvinyl chloride, or a mixture thereof reinforced with a fiber fabric mainly composed of at least one polymer selected from polyester or aromatic polyamide is preferred. Among these, a microporous membrane using polysulfone having high chemical, mechanical and thermal stability is particularly preferable. Specific examples include polysulfone composed of repeating units represented by the following chemical formula, and this polysulfone is preferable because of its advantages that the pore diameter is easy to control and dimensional stability is high.

  For example, the N, N-dimethylformamide solution of polysulfone is cast on a densely woven polyester fiber woven fabric or non-woven fabric (base fabric) with a certain thickness and then wet coagulated in water. By this, a microporous support membrane having micropores with a diameter of several tens of nm or less on the most part of the surface can be produced.

  The thickness of the above-described microporous support (including the base fabric) affects the strength of the composite semipermeable membrane and the membrane packing density when the membrane is used as an element. In order to obtain sufficient mechanical strength and sufficient film packing density, it is preferably in the range of 50 to 300 μm, more preferably in the range of 100 to 250 μm. If this thickness is too thin, it is difficult to obtain sufficient mechanical strength. Conversely, if it is too thick, it is difficult to obtain a sufficient film packing density. Moreover, it is preferable that the thickness of the part (henceforth a porous layer) except a base fabric among microporous supports exists in the range of 10-200 micrometers, More preferably, it exists in the range of 30-100 micrometers. .

  The film form of the porous layer can be observed with a scanning electron microscope, a transmission electron microscope, or an atomic microscope. For example, when observing with a scanning electron microscope, after removing the porous layer from the base fabric, it is cut by the freeze cleaving method to obtain a sample for cross-sectional observation. Ruthenium chloride (preferably ruthenium tetrachloride) may be thinly coated and observed with a high-resolution field emission scanning electron microscope (UHR-FE-SEM) at an acceleration voltage of 3 to 6 kV. As a high resolution field emission scanning electron microscope, an S-900 electron microscope manufactured by Hitachi, Ltd. can be used. The film thickness and surface pore diameter of the porous layer are determined from the obtained electron micrograph. In addition, the thickness and the hole diameter in this invention mean an average value.

  Next, the manufacturing method of the composite semipermeable membrane of this invention is demonstrated.

  The polyamide separation functional layer in the composite semipermeable membrane includes, for example, the above-described aqueous solution containing a polyfunctional amine, a polyfunctional acid halide, and the above-mentioned “cyclic aliphatic compound and / or aromatic compound having a specific substituent”. A polyamide skeleton is formed by interfacial polycondensation of these components on the surface of the microporous support membrane using the organic solvent solution (the organic solvent here is an organic solvent immiscible with water). Can be manufactured.

Here, the concentration of the polyfunctional amine in the polyfunctional amine aqueous solution is preferably in the range of 2.5 to 10% by weight, more preferably in the range of 3 to 5% by weight. Within this range, sufficient salt removal performance and water permeability can be imparted to the resulting semipermeable membrane, and the solute permeability coefficient can be 3 × 10 ⁻⁸ m / s or less. As long as the polyfunctional amine aqueous solution does not inhibit the reaction between the polyfunctional amine and the polyfunctional acid halide, a surfactant, an organic solvent, an alkaline compound, and an antioxidant may be contained. . Since the surfactant has the effect of improving the wettability of the surface of the microporous support membrane and reducing the interfacial tension between the aqueous amine solution and the nonpolar solvent, the organic solvent is a catalyst for the interfacial polycondensation reaction. In some cases, the interfacial heavy reaction can be efficiently performed by adding them.

  In order to perform interfacial polycondensation on the microporous support membrane, first, the above-mentioned polyfunctional amine aqueous solution is brought into contact with the surface of the microporous support membrane. The contact is preferably performed uniformly and continuously on the surface of the microporous support membrane. Specific examples include a method of coating a polyfunctional amine aqueous solution on a microporous support membrane and a method of immersing the microporous support membrane in a polyfunctional amine aqueous solution. The contact time between the microporous support membrane surface and the polyfunctional amine aqueous solution is preferably within a range of 1 to 10 minutes, and more preferably within a range of 1 to 3 minutes.

  After bringing the polyfunctional amine aqueous solution into contact with the surface of the microporous support membrane, the solution is sufficiently drained so that no droplets remain on the support membrane. If the liquid droplets remain on the support membrane, the liquid residual portion becomes a membrane defect after the formation of the separation functional layer, so that it is sufficient to produce a composite semipermeable membrane having no membrane defect and excellent membrane performance. It is necessary to drain the liquid. As a method of draining, for example, the porous support membrane after contacting with the polyfunctional amine aqueous solution is vertically gripped to allow the excess aqueous solution to flow down naturally, or air such as nitrogen is blown from an air nozzle to force A method of draining can be employed. Further, after draining, the membrane surface may be dried to remove a part of the attached water.

  Next, an organic solvent solution containing the polyfunctional acid halide and the above-mentioned “cycloaliphatic compound and / or aromatic compound having the specific substituent” is brought into contact with the support film after contacting with the polyfunctional amine aqueous solution. The skeleton of the cross-linked polyamide separation functional layer is formed by interfacial polycondensation of the polyfunctional amine, the polyfunctional acid halide, and the “cycloaliphatic compound and / or aromatic compound having the specific substituent”.

  The concentration of the polyfunctional acid halide in the organic solvent solution is preferably in the range of 0.01 to 10% by weight, and more preferably in the range of 0.02 to 2.0% by weight. Within this range, a sufficient reaction rate can be obtained, and the occurrence of side reactions can be suppressed. In addition, it is more preferable to include a carbonylation catalyst such as N, N-dimethylformamide in the organic solvent solution because interfacial polycondensation can be promoted.

  The organic solvent used here is an organic solvent that is immiscible with water, and is preferably capable of dissolving the polyfunctional acid halide and not destroying the microporous support membrane. Those inert to the compound and the polyfunctional acid halide can be used. Preferable examples of the organic solvent include hydrocarbon compounds such as n-hexane, n-octane and n-decane.

  In order to bring the organic solvent solution containing the polyfunctional acid halide and the “cycloaliphatic compound and / or aromatic compound having the specific substituent” into contact with the polyfunctional amine aqueous solution on the support membrane, The organic solvent solution may be coated by the same method as the coating of the functional amine aqueous solution on the surface of the microporous support membrane.

  As described above, interfacial polycondensation is performed by bringing an organic solvent solution containing a polyfunctional acid halide and the above-mentioned “cyclic aliphatic compound and / or aromatic compound having a specific substituent” into contact with each other on the porous support membrane. After forming the separation functional layer containing crosslinked polyamide, it is preferable to drain off excess organic solvent. As a method for draining, for example, a method in which a film is held in a vertical direction and excess organic solvent is allowed to flow down and removed can be used. In this case, the time for gripping in the vertical direction is preferably 1 to 5 minutes, and more preferably 1 to 3 minutes. If it is too short, the separation functional layer cannot be formed completely, and if it is too long, the organic solvent is excessively dried, so that defects are likely to occur and membrane performance is liable to deteriorate.

  In order to form the polyamide separation functional layer in the method for producing a composite semipermeable membrane of the present invention, for example, together with the polyfunctional acid halide described above, the “cycloaliphatic compound and / or aromatic having the specific substituent” is used. The organic solvent solution containing the “compound” may be brought into contact with the polyfunctional amine aqueous solution in contact with the support membrane on the support membrane and subjected to interfacial polycondensation. Alternatively, after the polyfunctional amine aqueous solution in contact with the support membrane is brought into contact with the polyfunctional acid halide on the support membrane to perform interfacial polycondensation to form a separation functional layer containing a crosslinked polyamide on the support membrane, The organic solvent solution containing the “cycloaliphatic compound and / or aromatic compound having the specific substituent” may be brought into contact with the polyamide of the separation functional layer on the support membrane to cause the reaction.

  In this case, the concentration of the polyfunctional acid halide in the organic solvent solution is preferably in the range of 0.01 to 10% by weight, and more preferably in the range of 0.02 to 2% by weight. preferable. This is because a sufficient reaction rate can be obtained when the content is 0.01% by weight or more, and the occurrence of side reactions can be suppressed when the content is 10% by weight or less. Further, it is more preferable that an acylation catalyst such as N, N-dimethylformamide is contained in the organic solvent solution because interfacial polycondensation is promoted.

  In the case where the “cycloaliphatic compound and / or aromatic compound having a specific substituent” is brought into contact after a substantial separation functional layer is formed by interfacial polycondensation of a polyfunctional amine and a polyfunctional acid halide, The amount is preferably 5 mol% or more based on the polyfunctional acid halide. If it is less than 5 mol%, the effect of blocking boron tends to be insufficient. Further, even if it is used in a large amount exceeding 100 mol%, the boron blocking effect cannot be further increased. Rather, the environmental burden due to a large amount of unreacted reagent and the economic burden for treatment increase, so at most. It is preferable that it is 100 mol% or less. And it is more preferable that it exists in the range of 5-50 mol%. On the other hand, the polyfunctional acid halide and the above-mentioned “cycloaliphatic compound and / or aromatic compound having a specific substituent” are made into a single organic solvent solution and brought into contact with the polyfunctional amine on the separation membrane to be separated. When forming the functional layer, the amount of the “cycloaliphatic compound and / or aromatic compound having the specific substituent” is 5 mol% or more based on the amount of the polyfunctional acid halide, and further 5 It is preferable to be in the range of ˜50 mol%, and it is particularly preferable to be in the range of 5 to 30 mol%. This is because by making the amount 5 mol% or more, the effect of improving the boron removal performance can be sufficiently exerted, and by making the amount 50 mol% or less, the salt removal performance and the permeation flux can be prevented from being lowered.

  The composite semipermeable membrane obtained by the above method is then heated with hot water in the range of 50 to 150 ° C., preferably in the range of 70 to 130 ° C., for 1 to 10 minutes, more preferably for 2 to 8 minutes. It is preferable to perform the hydrothermal treatment, and through this hydrothermal treatment step, the exclusion performance and water permeability of the composite semipermeable membrane can be further improved.

  The composite semipermeable membrane of the present invention produced as described above is used as a separation membrane in a semipermeable membrane element in which a separation membrane is provided. For example, the flat membrane-like composite semipermeable membrane of the present invention has a large number of holes, together with a raw water channel material such as a plastic net, a permeate channel material such as tricot, and a film for increasing pressure resistance as necessary. A spiral type composite semipermeable membrane element is produced by spirally winding around the perforated cylindrical water collecting pipe.

  Further, the composite semipermeable membrane element is used as a fluid separation element in a fluid separation device provided with a fluid separation element. For example, the above composite semipermeable membrane elements are connected in series or in parallel and housed in a pressure vessel to produce a composite semipermeable membrane module, and a pump that supplies raw water to these composite semipermeable membrane elements and composite semipermeable membrane modules In addition, a fluid separation device is manufactured in combination with a device for pretreating the raw water. By using this fluid separator, the raw water is subjected to a semi-permeable membrane treatment, so that it is separated into permeated water such as drinking water and concentrated water that has not permeated the membrane, and water suitable for the target water quality can be obtained. .

  The higher the operating pressure of the fluid separator, the higher the boron removal rate, but at the same time the energy required for operation increases, and the durability of the composite semipermeable membrane tends to decrease. The operating pressure for permeation is preferably 1.0 MPa or more and 10 MPa or less. As the temperature of the water to be treated supplied to the semipermeable membrane increases, the boron removal rate tends to decrease, and the membrane permeation flux tends to decrease as the temperature decreases. Therefore, the temperature is preferably 5 ° C. or higher and 45 ° C. or lower. Further, as the pH of the supplied water increases, boron in the supplied water dissociates into borate ions and the boron removal rate improves. However, in the case of feed water having a high salt concentration such as seawater, there is a concern that scales such as magnesium may be generated as the pH is higher, and membrane deterioration due to high pH operation is a concern. Accordingly, the pH of the feed water is preferably in the neutral range.

  The characteristics of the composite semipermeable membranes in the examples and comparative examples were obtained by operating seawater (TDS concentration of about 3.5%, boron concentration of about 5.0 ppm) adjusted to a temperature of 25 ° C. and pH 6.5 on the composite semipermeable membrane. Membrane filtration was performed by supplying at a pressure of 5.5 MPa, and the water quality of the obtained permeated water and the quality of the supplied water were measured. The measured values and calculation formulas are as follows.

(TDS removal rate)
The TDS concentration in the permeated water and the TDS concentration in the supply water are measured, and the TDS removal rate (%) is calculated by the following equation.

(Membrane permeation flux)
The membrane permeation flux (m ³ / m ² / day) is expressed by converting the membrane permeation amount of the supplied water (seawater) into a permeation amount per cubic meter of membrane surface per day (cubic meter).

(Boron removal rate)
The boron concentration in the feed water and the boron concentration in the permeated water are analyzed with an ICP emission spectrometer, and the boron removal rate (%) is obtained from the following equation.

(TDS transmission coefficient)
The TDS transmission coefficient (m / s) was calculated by the following calculation formula described in “Membrane Processing Technology Series”, first volume, p171, supervised by Masayuki Nakagaki, Fuji Techno System (1991).

  The polymer composition of the separation functional layer in the composite semipermeable membrane can be evaluated by the following method.

The presence of the “cycloaliphatic group and / or aromatic group having a specific substituent” in the polyamide molecular chain of the separation functional layer is determined by measuring the solid functional NMR spectrum of the separation functional layer separated from the support membrane. Alternatively, a sample hydrolyzed by heating with a strong alkaline aqueous solution can be analyzed by HPLC measurement or ¹ H-NMR spectrum measurement.
(Reference example)
Compounds 1 to 5 listed in Table 1 were synthesized by the method described below.

Reference Example 1 Synthesis of (4-chlorocarbonylmethoxyphenoxy) acetyl chloride (Compound 1) Hydroquinone 5.51 g (50.0 mmol) and methyl bromoacetate 16.1 g (105.0 mmol) were mixed with N, N-dimethylformamide ( Hereinafter, abbreviated as DMF.) Dissolved in 50.0 ml, added 20.7 g (150.0 mmol) of potassium carbonate and stirred for 12 hours. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layers were combined, washed with an aqueous sodium hydrogen carbonate solution, water and saturated brine, and dried over anhydrous sodium sulfate. The desiccant was removed and the filtrate was concentrated under reduced pressure. The resulting residue was recrystallized from methylene chloride / n-hexane to obtain 10.7 g of colorless crystals.

  7.80 g of this crystal was dissolved in 30.0 ml of methanol, and 46.0 ml (92.0 mmol) of 2N aqueous sodium hydroxide solution was added over 20 minutes, followed by stirring at room temperature for 12 hours. To the reaction mixture, hydrochloric acid was added little by little under ice-cooling to make it acidic (pH 2), and then methanol was distilled off under reduced pressure. The precipitated solid was filtered and dried under reduced pressure to obtain 6.94 g of a white solid.

  2.98 g of this white solid was dissolved in 40.0 ml of dichloroethane, 3.39 ml (39.5 mmol) of oxalyl dichloride and 0.01 ml of DMF were added, and the mixture was stirred at room temperature for 5 hours. After the reaction mixture was filtered, the filtrate was concentrated under reduced pressure, and the resulting residue was recrystallized from methylene chloride / n-hexane to obtain 1.84 g (6.99 mmol) of light brown crystals of Compound 1. The total yield was 45%.

(Reference Example 2)
Compound 2 was synthesized in the same manner as in Reference Example 1 except that hydroquinone was changed to resorcinol in Reference Example 1.

(Reference Example 3)
Compound 3 was synthesized in the same manner as in Reference Example 1 except that hydroquinone was changed to phloroglucinol in Reference Example 1.

(Reference Example 4)
Compound 4 was synthesized in the same manner as in Reference Example 1, except that hydroquinone was changed to 1,2,4-trihydroxybenzene in Reference Example 1.

Reference Example 5 Synthesis of (4-chlorocarbonylmethoxycyclohexyloxy) acetyl chloride (Compound 5) Hydroquinone 5.51 g (50.0 mmol) and methyl bromoacetate 16.1 g (105.0 mmol) were dissolved in DMF 50.0 ml. Then, 20.7 g (150.0 mmol) of potassium carbonate was added and stirred for 12 hours. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layers were combined, washed with an aqueous sodium hydrogen carbonate solution, water and saturated brine, and dried over anhydrous sodium sulfate. The desiccant was removed and the filtrate was concentrated under reduced pressure. The resulting residue was recrystallized from methylene chloride / n-hexane to obtain 10.7 g of colorless crystals.

  After adding 20.0 ml of ethanol to 254 mg of this crystal and 526 mg (2.0 mmol) of rhodium trichloride trihydrate and stirring at room temperature for 2 hours, 20.0 ml of an ethanol solution of 378 mg (10.0 mmol) of sodium borohydride was added. The solution was added dropwise over 30 minutes and stirred at room temperature for 12 hours. After the reaction mixture was filtered, 1N hydrochloric acid was gradually added to the filtrate to make it acidic (pH 2), and ethanol was distilled off under reduced pressure. Subsequently, the mixture was extracted with ethyl acetate, the organic layers were combined, washed with water and saturated brine, and dried over anhydrous sodium sulfate. Removal of the desiccant and concentration under reduced pressure gave 171 mg of colorless oil.

  This oil was dissolved in 20.0 ml of methanol, 5.93 ml of 1N aqueous sodium hydroxide solution was added dropwise over 5 minutes, and the mixture was stirred overnight at room temperature. Methanol was distilled off, 1N hydrochloric acid was added little by little under ice cooling to make it acidic (pH 2), and the mixture was extracted 3 times with ethyl acetate. The organic layers were combined, washed with water and saturated brine, and anhydrous. Sodium sulfate was added and dried. Removal of the desiccant and concentration under reduced pressure gave 122 mg of a colorless oil.

  118 mg of this oil was dissolved in 10.0 ml of dichloroethane, 0.132 ml (1.52 mmol) of oxalyl dichloride and 0.01 ml of DMF were added, and the mixture was stirred at 40 ° C. for 1 hour. The reaction mixture was concentrated under reduced pressure to obtain 170 mg of a yellow oil of compound 5. The total yield was 47%.

(Reference Example 6)
Compound 6 was synthesized in the same manner as in Reference Example 1 except that hydroquinone was changed to methyl 3-hydroxybenzoate in Reference Example 1.

(Reference Example 7)
Compound 7 was synthesized in the same manner as in Reference Example 1 except that hydroquinone was changed to dimethyl 5-hydroxyisophthalate in Reference Example 1.

(Reference Example 8)
Compound 8 was synthesized in the same manner as in Reference Example 1, except that hydroquinone was changed to methyl 3,5-dihydroxybenzoate in Reference Example 1.

(Examples 1-15, Comparative Examples 1-3)
A 15.3% by weight dimethylformamide (DMF) solution of polysulfone was cast on a polyester nonwoven fabric (air permeability 0.5 to 1 cc / cm ² · sec) at room temperature (25 ° C.) to a thickness of 200 μm, and immediately purified. A microporous support membrane was prepared by immersing in water and allowing to stand for 5 minutes.

  The microporous support membrane (thickness 210 to 215 μm) thus obtained was immersed in a 3.4 wt% aqueous solution of m-phenylenediamine for 2 minutes, and then the support membrane was slowly pulled up in the vertical direction. Nitrogen was blown from the air nozzle to remove excess aqueous solution from the surface of the support membrane. Thereafter, an n-decane solution containing 0.175% by weight of trimesic acid chloride and the concentrations and types of cycloaliphatic compounds or aromatic compounds described in Table 2 was applied so that the surface was completely wetted and allowed to stand for 1 minute. I put it. Next, in order to remove excess solution from the membrane, the membrane was held vertically for 1 minute and drained. Thereafter, after washing with hot water at 90 ° C. for 2 minutes, it was immersed in an aqueous sodium hypochlorite solution adjusted to pH 7 and a chlorine concentration of 200 mg / l for 2 minutes, and then in an aqueous solution having a sodium bisulfite concentration of 1,000 mg / l. The excess sodium hypochlorite was removed by reduction. Furthermore, this membrane was rewashed with hot water at 95 ° C. for 2 minutes.

  When the obtained composite semipermeable membrane was evaluated, the membrane permeation flux, TDS removal rate, boron removal rate, and TDS permeability coefficient were values shown in Table 2, respectively. The relationship between the membrane permeation flux and the boron removal rate is shown in FIG.

  The composite semipermeable membrane of the present invention can achieve a high salt removal rate and a high permeation flux, and also exhibits high blocking performance against non-dissociated substances in a neutral region such as boron. It can be suitably used for applications such as treating cooling water and plating wastewater, and using desalinated high-concentration brine or seawater to produce drinking water and the like.

Claims (10)

A composite semipermeable membrane having a polyamide separation functional layer formed on a microporous support membrane, wherein the polyamide constituting the polyamide separation functional layer has a cyclic aliphatic group and / or an aromatic group in the molecular chain. The cycloaliphatic group and / or the aromatic group has two or more groups represented by any of the following formulas (1) or (2) as a substituent, and the substituent: At least one of them is a group represented by the following formula (1).

(In the formula, n represents 0 or 1. X represents O, S, or NR5. R ¹ , R ² , and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. However, R ¹ And at least one of R ² is a hydrogen atom, and R ³ and R ⁴ are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aromatic group which may have a substituent other than a carboxy group. A ring structure may be formed by covalent bonding between atoms of R ¹ and R ^3. A represents a hydroxyl group or an amino group in a polyamide molecule, and is in at least one of two or more substituents. A is an amino group in the polyamide molecule.) The polyamide constituting the polyamide separation functional layer has a polyfunctional amine aqueous solution and two or more groups represented by any of the following formulas (3) or (4) as substituents, By contacting an organic solvent solution containing a cycloaliphatic compound and / or an aromatic compound, which is a group represented by the following formula (3), on a microporous support membrane and interfacial polycondensation The composite semipermeable membrane according to claim 1, which is the obtained crosslinked polyamide.

(In the formula, n represents 0 or 1. X represents O, S, or NR ^5. R ¹ , R ² , and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ^At least ^one of R ¹ and R ² is a hydrogen atom, and R ³ and R ⁴ are a hydrogen atom or an alkyl or aromatic group having 1 to 12 carbon atoms that may have a substituent other than a carboxy group. R ¹ and R ³ may be covalently bonded to form a ring structure. Z represents a halogen atom.) The cycloaliphatic compound or the aromatic compound each has one or more groups represented by the formula (3) and the group represented by the formula (4) as substituents; and 2-chlorocarbonylmethoxybenzoyl chloride, 3-chlorocarbonylmethoxybenzoyl chloride, 4-chlorocarbonylmethoxybenzoyl chloride, 2,3-bischlorocarbonylmethoxybenzoyl chloride, 2,4-bischlorocarbonylmethoxybenzoyl chloride, 2,5- Bischlorocarbonylmethoxybenzoyl chloride, 2,6-bischlorocarbonylmethoxybenzoyl chloride, 3,4-bischlorocarbonylmethoxybenzoyl chloride, 3,5-bischlorocarbonylmethoxybenzoyl chloride, 2-chlorocarbonylmethoxycycle Hexanecarbonyl chloride, 3-chlorocarbonylmethoxycyclohexanecarbonyl chloride, 4-chlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,3-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,4-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,5- Bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 2,6-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 3,4-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 3,5-bischlorocarbonylmethoxycyclohexanecarbonyl chloride, 3-chlorocarbonylmethoxyphthalo Yl chloride, 4-chlorocarbonylmethoxyphthaloyl chloride 2-chlorocarbonylmethoxyisophthaloyl chloride, 4-chlorocarbonylmethoxyisophthaloyl chloride, 5-chlorocarbonylmethoxyisophthaloyl chloride, 2-chlorocarbonylmethoxyterephthaloyl chloride, 1-chlorocarbonylmethoxycyclohexane-2, 3-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-2,4-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-2,5-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-2,6-dicarbonyl dichloride 1-chlorocarbonylmethoxycyclohexane-3,4-dicarbonyl dichloride, 1-chlorocarbonylmethoxycyclohexane-3,5-dicarbonyl dichloride, The composite semipermeable membrane according to claim 2, wherein the composite semipermeable membrane is at least one selected from the group consisting of: The cycloaliphatic compound or aromatic compound has two or more groups represented by the formula (3) as substituents, and (2-chlorocarbonylmethoxyphenoxy) acetyl chloride, (3-chloro Carbonylmethoxyphenoxy) acetyl chloride, (4-chlorocarbonylmethoxyphenoxy) acetyl chloride, (2,3-bischlorocarbonylmethoxyphenoxy) acetyl chloride, (2,4-bischlorocarbonylmethoxyphenoxy) acetyl chloride, (3,5 -Bischlorocarbonylmethoxyphenoxy) acetyl chloride, (2-chlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (3-chlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (4-chlorocarbonylmethoxy) (Cyclohexyloxy) acetyl chloride, (2,3-bischlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (2,4-bischlorocarbonylmethoxycyclohexyloxy) acetyl chloride, (3,5-bischlorocarbonylmethoxycyclohexyloxy) acetyl chloride , (2-chlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, (3-chlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, (2,3-bischlorocarbonylmethoxycyclopentanyloxy) acetyl chloride, (2,4 The composite semipermeable membrane according to claim 2, which is at least one selected from the group consisting of -bischlorocarbonylmethoxycyclopentanyloxy) acetyl chloride. Membrane flow rate (m ³ / m ² / day) and boron removal rate when seawater of 25 ° C., pH 6.5, boron concentration 5 ppm, TDS concentration 3.5 wt% was permeated at an operating pressure of 5.5 MPa %) Satisfies the following expression (5) and / or satisfies the following expressions (6) and (7): The composite semipermeable membrane according to claim 1, wherein:

TDS permeability coefficient when passing seawater at 25 ° C., pH 6.5, boron concentration 5 ppm, TDS concentration 3.5 wt% at an operating pressure of 5.5 MPa is 0.1 × 10 ⁻⁸ m / s or more 3 The composite semipermeable membrane according to claim 1, wherein the composite semipermeable membrane is not more than × 10 ⁻⁸ m / s. The method for producing a composite semipermeable membrane according to claim 1 by forming a polyamide separation functional layer on a microporous support membrane, comprising a polyfunctional amine aqueous solution, a polyfunctional acid halide, and the formula ( Cycloaliphatic having two or more groups represented by either 3) or (4) as substituents, and at least one of the substituents being a group represented by the formula (3) Forming a polyamide separation functional layer by bringing a compound and / or an aromatic compound into contact with an organic solvent solution containing 5 mol% or more of the polyfunctional acid halide on the microporous support membrane and interfacial polycondensation A method for producing a composite semipermeable membrane, comprising: A semipermeable membrane element comprising a separation membrane, wherein the separation membrane is the composite semipermeable membrane according to claim 1. A fluid separation device comprising a fluid separation element, wherein the fluid separation element is the semipermeable membrane element according to claim 8. In the method of processing water by letting a semipermeable membrane pass, the composite semipermeable membrane of Claim 1 is used as a semipermeable membrane, The water treatment method characterized by the above-mentioned.

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